williatw wrote:Just out of curiosity...is it reasonably possible that both EM Drive & Mach Thruster drive will turn out to work? Or are their "theories" of operation in some way incompatible?

My understanding is that the proposed theory for the workings of the EmDrive involves rejecting wave-particle duality. In other words, it claims photons occupy a specific location in space at any given time and that something else (unspecified) is the source of strangeness.

The Mach Effect is based on Mach's Principle, which, put vaguely, is "mass out there influences inertia". So there doesn't seem to be much common ground.

His theory is that Acoustic resonances in the quantum vacuum are directly responsible for atomic structure Applying a time-varying electromagnetic field using simulation and experimentation He then has force predictions

Lawrence Krauss argues with White on the quantum physics principles. at 4:00 hours into the video. Robert Zubrin then follows up about White using 100 times more thrust per kilowatt in the proposed mission beyond what they have measured.

The SpaceDrive Project – First Results on EMDrive and Mach-Effect Thrusters

Tajmar is finding more magnetic interaction from cables. He is not conclusively saying that is all that is happening with EMdrive or Mach Effect but he thinks it is a significant error source for such tiny thrust measurements.

Propellantless propulsion is believed to be the best option for interstellar travel. However, photon rockets or solar sails have thrusts so low that maybe only nano-scaled spacecraft may reach the next star within our lifetime using very high-power laser beams. Following into the footsteps of earlier breakthrough propulsion programs, we are investigating different concepts based on non-classical/revolutionary propulsion ideas that claim to be at least an order of magnitude more efficient in producing thrust compared to photon rockets. Our intention is to develop an excellent research infrastructure to test new ideas and measure thrusts and/or artefacts with high confidence to determine if a concept works and if it does how to scale it up. At present, we are focusing on two possible revolutionary concepts: The EMDrive and the Mach-Effect Thruster. The first concept uses microwaves in a truncated cone-shaped cavity that is claimed to produce thrust. Although it is not clear on which theoretical basis this can work, several experimental tests have been reported in the literature, which warrants a closer examination. The second concept is believed to generate mass fluctuations in a piezo-crystal stack that creates non-zero time-averaged thrusts. Here we are reporting first results of our improved thrust balance as well as EMDrive and Mach-Effect thruster models. Special attention is given to the investigation and identification of error sources that cause false thrust signals. Our results show that the magnetic interaction from not sufficiently shielded cables or thrusters are a major factor that needs to be taken into account for proper µN thrust measurements for these type of devices.

EM drive just got peer reviews and it does not look good.Unfortunately, a new round of research out of Germany is casting some big doubts on those early results. In a new research paper the team argues that not only does the engine not actually produce any thrust, but that earlier tests may have erroneously detected thrust due to “electromagnetic interaction” between the engine and Earth’s own magnetic field. Oops!

paperburn1 wrote:EM drive just got peer reviews and it does not look good.Unfortunately, a new round of research out of Germany is casting some big doubts on those early results. In a new research paper the team argues that not only does the engine not actually produce any thrust, but that earlier tests may have erroneously detected thrust due to “electromagnetic interaction” between the engine and Earth’s own magnetic field. Oops!

but if it works in orbit that still could be useful.

but if it works in orbit that still could be useful.

That statement rings true to me. How would one go about designing a thruster based on this interaction with Earth's magnetic field? Some compact propellantless device that could counter drag on a satellite orbiting at 100 - 200 km altitude would be very useful indeed.

Aero wrote:That statement rings true to me. How would one go about designing a thruster based on this interaction with Earth's magnetic field? Some compact propellantless device that could counter drag on a satellite orbiting at 100 - 200 km altitude would be very useful indeed.

Here is my simplified down answer: There are two important things to know to answer that question. First, the Earth's magnetic field is actually weak relatively speaking. Second, magnetic fields lose strength rapidly over distance (inverse-square law). With those 2 bits of information in mind, you would not have enough magnetic field to react against to overcome gravity and even if you were able to overcome it at a specific orbit, all like-devices would be locked around that orbit roughly, never to be used for solar exploration or interstellar exploration.

Anyone here still holding out any hope that Sonny White will succeed in pulling a rabbit out of his hat and proving EmDrive is valid? Understand that Tajmar hasn't exactly killed it yet just seems to be saying you can't rule out some kind of interference causing the apparent "thrust" results? Maybe White's stronger power will help, but personally I think until someone orbits a satellite with a truly autonomous system and switches it on to see what happens the pro-EmDrive people (White) are just blowing smoke. Same with the Mach drive folks. Can't cost that much to put up a small sat containing the apparatus.

williatw wrote:Anyone here still holding out any hope that Sonny White will succeed in pulling a rabbit out of his hat and proving EmDrive is valid? Understand that Tajmar hasn't exactly killed it yet just seems to be saying you can't rule out some kind of interference causing the apparent "thrust" results? Maybe White's stronger power will help, but personally I think until someone orbits a satellite with a truly autonomous system and switches it on to see what happens the pro-EmDrive people (White) are just blowing smoke. Same with the Mach drive folks. Can't cost that much to put up a small sat containing the apparatus.

My problem with White has always been that he appropriates someone else's experiment/research then attempts to attribute any results claimed to his QVF model. If you look at White's EmDrive work, his initial attempts found the same measurement for both their device as well as their control (which is pretty much what happen with Tajmar). Instead of trying to explain why that could be, he doubled down, building another device and retooling his theory to fit unobserved (to that point) thrust. The lone published paper by White on the EmDrive lacked proper error analysis and to further muddy the waters, was published to a propulsion journal (target audience is engineers) with a poor peer review process instead of a well known/respected physics journal (target audience is phycisists). Even before the EmDrive, he was looking at Woodward's work and trying to shoehorn it into his QVF model. The pursuit to further our understanding can be a noble one, however; the actions taken within that pursuit ultimately decide.

TDPerk wrote:Hopefully this will result in more energy going to Woodward's MET concept.

Not according to your posted link:

As for the mach effect thruster, it is also not doing well. Several high level physics heavy presentations, including one by Dr. Rodal, that make the claim that the mach effect thruster cannot work as Woodward describes and is likely a self-interaction effect. Tajmar's group thinks it doesn't work and will report tomorrow. Then in my presentation I showed how Woodward's thrust signature can be generated in a simulation of the device using first principles and simple mechanics - and how everything equals out to zero at the end. I was also able to build a crude 3 DOF device that produced the same "thrust" signature.

It might be a decent shot to try a different design, like the magnetic oscillator I've mentioned. While there is magnetic issues to be dealt with the cap stack could be on an air bearing or something and thus have no space for Dean drive effects in the piezo stack.

My google fu has been short on finding me maximum possible frequencies it could run at, and all I can remember from a community college class is it should be more than a few KHz.

TDPerk wrote:Hopefully this will result in more energy going to Woodward's MET concept.

Not according to your posted link:

As for the mach effect thruster, it is also not doing well. Several high level physics heavy presentations, including one by Dr. Rodal, that make the claim that the mach effect thruster cannot work as Woodward describes and is likely a self-interaction effect. Tajmar's group thinks it doesn't work and will report tomorrow. Then in my presentation I showed how Woodward's thrust signature can be generated in a simulation of the device using first principles and simple mechanics - and how everything equals out to zero at the end. I was also able to build a crude 3 DOF device that produced the same "thrust" signature.

So bad news all around...not very happy about this.

I know Tajmar and I believe Rodal's work has already been refuted (shown not to be able to support the conclusions they come to) by Dr. Woodward.

TDPerk wrote:Hopefully this will result in more energy going to Woodward's MET concept.

Not according to your posted link:

As for the mach effect thruster, it is also not doing well. Several high level physics heavy presentations, including one by Dr. Rodal, that make the claim that the mach effect thruster cannot work as Woodward describes and is likely a self-interaction effect. Tajmar's group thinks it doesn't work and will report tomorrow. Then in my presentation I showed how Woodward's thrust signature can be generated in a simulation of the device using first principles and simple mechanics - and how everything equals out to zero at the end. I was also able to build a crude 3 DOF device that produced the same "thrust" signature.

So bad news all around...not very happy about this.

I know Tajmar and I believe Rodal's recent work has already been refuted (shown not to be able to support the conclusions they come to) by Dr. Woodward.